Altimetric automatic controlling device for carburetors for aeroplane motors



May 19, 1931. A. BOULADE 1,806,280

ALTIMETRIC AUTOMATIC CONTROLLING DEVICE FOR GARBURETORS FOR AEROPLANE MOTORS Filed April 10, 1924 Invenior Patented ltdny lid, ilddl barren .dl-l'lfiml' BOULMDE OF LYOlZl', FRANCE, ASSIGNGR 1'0 SOGETE ID'U UMB'UJBIATEUH V ZENITH, F LYON, FRANCE A MTIMETEIQ AUTUMATIG CONTROLLING DEVICE FOR CARBUI-L'E'Eflfifi FOR- .AEBOPLMUE MQTORS 7 Application filed April 10, 1924, Serial No. 705,651, and in France April 12, 1933.

it is knownthat in carburetors for aeroplane engines various adjustments are necessary in view of the varying altitude of the aeroplane.

Amongst these, especial mention may be made of those which have for their object the weakening of the mixture produced and the increase of compression in accordance with the altitude of the" aeroplane. This latter 0 oration generally consists in the limitation or the compression of the motor on the ground by reducing the gas opening.

It is advantageous that should be automatically controlled, so that greater accuracy may be obtained, and a considerable amount of worry and the possibility of making mistakes obviated.

Various methods for efiecting these automatic controls have been suggested par ticular, the useo't barometric capsules. Ap paratus comprising such capsules are very delicate in their working, and furthermore, it they are to be kept within reasonable dimensions, they do not permit of the finest adjustments being carried out. Now, in order to operate the corrector of a carburetor as well as the throttle or any other member which enables the compression to be reduced on the ground, considerable trouble is neces sary, especially if there are several carburetors to be controlled.

The present invention relates to a device for the automatic control of the carburetor,

-which combines the advantages of light weight and small bulk and which enables etlorts to be made as considerable as may be desired, while at the same time preserving great accuracy. 7. I

The accompanying drawing shows diagrammatically a constructional form of the invention.

lhe device is composed of a limited numher of parts, namely: a cylinder it, partly open at one end and closed at the other end by a dome 1",. this cylinder encloses a piston 2 and a helical spring 3 which operates to continuously force back the piston 2 towards the dome 1. The piston 2-is coupled by a pin 5 to a small connecting rod d which actuates, directly or otherwise, the member or memthese operationsbers of the carburetor which have to be automatically regulated in accordance with the altitude attained by the -aeroplane.

The dome 1 is divided into two chambers, 6 and 7 by a membrane 8, fined to the wall of the dome in such a manner that no communication between the two chambers is possible. The diaphragm 8 which separates the a paratus into two parts is preferably m n/ fact rubber. It is only required that this diaphragm be gas tight, there being no requirement for strength because it is not subjected to any strain, the pressure being practically the same on both sides, and the center of the diaphragm moving but very little.

To the centre of this membrane is lined a bearing piece 8, to which is jointed a connect.

ing link 9, which in its turn is "ointed to the extremity of the armlO of a be 1 crank lever pivoted at 12, the other arm of which being provided with a needle or valve 11, which is designed to close the orifice of a tube 13, which conveys into the chamber 6 a gaseous or liquid fluid at a pressure always higher than that in the chamber 7.

The top of the dome is provided with an opening which allows the admission into the chamber 7 either of air at atmospheric pressure or compressed, or ofa gas at any pressure desired. 'lhis opening, after the desiredv fluid has been admitted, is closed by a stop 0 er 7. V

- The method of working of the device is as follows: in the first place the upper chamber 7 is iilled with air or gas at atmospheric or at any other suitable pressure. As the tube 13 introduces a fluid at a pres sure higher than that in chamber 7, this fluid endeavours to penetrate into the chamber 6 and the membrane 8 rises as soon as the pressure in this chamber exceeds, by however little, the pressure in i the chamber 7. The lifting of this membrane causes the lifting of the connecting rod 9 and a pivotal movement of the bell crank lever 10, 10 so that the valve 11 closesthe orifice oi the ipe 13 and cuts 0d the supply of the fluid un er pressure.

The result is to establish a state of equilib l altitude attained by the aeroplane, the plston V the tube 13 compensates. for the discharges,

leakage-or displacement caused by the piston 2, the pressure in the chamber 6 remaimng in every case strictly equalto that in the chamber Above the piston 2 a constant pressure is therefore maintained equal to the pressure H originally created in the chamber 7. Since below this piston the pressure is the atmospheric pressure I-I corresponding to the descends, thereby compressing the spring 3 to a point at which the pressure of this sprmg is equal to the difierence IT -H between the original pressure and the pressure correspondin to the altitude of the aeroplane.

The a timetric contrcl of the desired members of .the carburetor is therefore 'efl'ected exactly in accordance with this difierence in pressure. The'length of piston stroke to be employed is determined by the characteristic features ofthe spring, while so far as the value of the effort to be produced is concerned, this may be as great as desired by giving the piston a suitable area.

. In the drawing the apparatus is arranged so astobe placed vertically but it may be arbrane is given only chamber 6 may ranged horizontally.

v The mechanism s own for the closing of the orifice of 13*by displacements of the memby way of an example, arlld agly other suitab e means may be em- P e v 'I he fluid under pressure which enters the with advantagebe the gases produced in t inders of t e aero lane motor. A tube.13 would efiect in a simple manner the admission fromv the cylinder ofi'the motor.

If it is desired to utilize the maximum pres sure of the explosion,the tube would be connected to the upper part of the cylinder. Ifon the contrary ,it is desired to make 'use of only a part of the explosion pressure, which is more suitable, the tube would be arranged in such a manner that it would not be uncovered by the piston until'the latter had already effooted part of its stroke. This may conveniently be accomplished by connecting a suitable'conduit 15 with the interior of the internal combustion engine cylinder 16- at the desired point intermediate'its'ends, and leading this conduit toa valve casingfl-T. .Within this casing there may be provided an upwardly opening valve'18 serving as a check valve and permittingthe How of fluid under pressure from the cylinder into the up er portion of the valve casing. The second va ve 19 may be considered as a pressure release valve, tending'to vent accumulated pressure tothe atmosphere after it passes a predetermined point. Conveniently, both valves may be spring loaded whereby the desired conditions of operation may be efi'ectively obtained. The upper portion of the valve case explosion in one of the cyl.-'

to secure by Letters neodaeo ing 17 is in turn connectedby the tube 13, previously described, to the dome of the cylinder 1. v

It will be understood by those skilled in the art that the device hereindescribed is efiective through the rod 4 for producing movement of any part of the carburetor which it is desired to control. The intial pressure in the chamber 7 may be' of any value desired according to the results to be obtained, and the inlet'13 will maintain a similar pressure in the chamber 6 as the piston 2 moves downwardly, and thereby increases the area of the chamber 6, or as leakage past the piston takes place, If the. pressure in the chamber? is equivalent to atmospheric pressure at sea level, then as soon as the aeroplane rises to such an altitude that the'pressure in chambers 6 and 7 is greater than atmospheric pressure at that altitude, plus the pressure of the spring, the piston 2 will move downwardly and effect the desired operation of the carburetor. This operation may comprise leaning out the mixture or'permitting a wider opening of the throttle at higher altitudes than nearer the ground. By reason of the provision of a spring, the amount of movement of the piston will be proportionate to pressure diflerences in the chambers 6 and 7 on one hand, and atmospheric pressure at the level of-the apparatus, plus the pressure of the spring, on the other hand. Obviously, the

length of stroke may be varied by changing v .What I claim as my'lnvention and desire Statesis: 1

1. Alimetric' automatic controlling device for aeroplane motor carburetors, comprising, in combination, a cylinder open at its lower end and terminating atits upper extremity in a chamber, a piston movably mounted in said cylinder, a spring operating to move said piston towards said chamber, a rod connecting said piston to the operating control for the carburetor, means for supplying a Patent of the United fluid medium to said chamber, the pressure of said medium in said chamber compressing the spring according as the external pressure exercised on the lower surface of the piston diminishes, and'pressure responsive means U in combination in said chamber :lor controlling the admission of said medium thereto.

2. Altimetric automatic controlling device for aeroplane motor carburetors, comprising, a cylinder open at its lower end and provided with a chamber at its upper extremity, a piston movably mounted in said cylinder, a spring operating to move said piston towards said chamber, a'rod connecting said piston to the operating control for the carburetor, a second closed chamber above said first mentioned chamber, a flexible membrane between said chambers, a tube for admitting fluid to said first-mentioned chamber,

a valve for opening or closin the inlet or said tube to said chamber, an means oper ated by the said flexible membrane for operating said valve.

3. In an adiusting apparatus for carburetors, a cylin er, a piston movable therein, a pressure chamber tor subjecting said piston on one side to predetermined pressure conditions irrespective of altitude, a second pressure chamber, means interposed between said chambers for controlling the pressure in said chamber, said first-named piston on its opposite side being subjected to pressures varying With the altitude, and means for connecting said piston to a control, substantially described,

in an adjusting apparatus for carburotors, a cylin er, a piston movable therein, apressure chamber for subjecting said piston on one side to predetermined pressure conditions irrespective of altitude, a second chain. her having a predetermined pressure initially established therein, pressure responsive means interposed between said chambers, for controllim the pressure in said chamber, said first-name piston on its opposite side being subjected to pressures varying "with the alti-= tude, and means for connecting said iston to a control, substantially as described? in an adjusting apparatus for carburetors, a pistommeans for automatically sub jecting said piston on one side to an invariable pressure condition, irrespective of the piston position, leakage or altitude, said means comprising constant pressure control chambers, and an interposed diaphragm-for controlling" "no pressure in said chambers, the piston on o osite side being subjected to pressure conditions varying with the altitude, and means'tor connecting said piston to a control.

i, in an adjusting'apparatus :lor carburetors, a piston, means for subjecting said piston on one side to an invariable pressure irrespective oil altitude, said piston on the opposite side being subjected to cpressure conions vowing with the altitu "e, means tor connecting said piston to a portion oi the carburetor to be controlled, and a pressure responsive diaphragm for. maintag said invariable pressure,

If, lln an adjusting apparatus tor cariou ification.

AhliUNllt VGER'HHFIGATE oi eoR'ReoTioN.

- Patent No. mouse. Grahtedhiay 19,1931,

ANIGNEN eoULADE.

it is'hea'ehy certifledthot error appears in the printed specification oi the above numbered patent requiring. correction as follows: Page 3, line 26, claim 3; and lines 39 and 40, claim 4,'for "chamber, said first named"'read firstnamed chamber,; and that the said Letters Patent should be readwith these corrections therein that'the some may conform to the record of the case in the ?81K%M Mike. I

Signed endfoealed this Est ay oi eptemher, A; D. .1931.

M. 3. Moor (Seei) x Acting Commissioner of Patents. 

